The puerile side of mobile-phone gaming has surfaced with Apple’s allowance of flatulence-based games for iPhone.

Several dozen have suddenly appeared, and topping the list in popularity is one called “iFart Mobile,” which lets you program an iPhone to make loud, gassy sounds like “Quack,” “Double Quack” or “Howard the Duck,” among other cheesy names.

A favorite feature is the time-delayed “Sneak Attack” for pulling pranks on unsuspecting souls by hiding the iPhone somewhere near them. There’s also a “Security Alarm” feature that emits the colon belch of your choice if someone tries to steal the device.

This week, iFart Mobile has been the iPhone’s top paid application, costing 99 cents to download. Following not far behind is “Pull My Finger,” an electronic whoopee cushion of sorts that combines flatulence sounds with music and animation. It also sells for 99 cents, and like “iFart Mobile” is available through the iTunes App Store.

Other flatulence-based games out there include “Fart Box,” “Fart Button,” and “iToot.” They are among several adult-oriented entertainment applications Apple is permitting into the App Store.